We have previously shown that when observers are presented with complex
natural scenes that contain a number of objects and people, observers look
mostly at the eyes of the people. Why is this? It cannot be because eyes
are merely the most salient area in a scene, as relative to other objects
they are fairly inconspicuous. We hypothesized that people look at the eyes
because they consider the eyes to be a rich source of information. To test
this idea, we tested two groups of participants. One set of participants,
called the Told Group, was informed that there would be a recognition
test after they were shown the natural scenes. The second set, the Not
Told Group, was not informed that there would be a subsequent recognition
test. Our data showed that during the initial and test viewings, the
Told Group fixated the eyes more frequently than the Not Told group,
supporting the idea that the eyes are considered an informative region
in social scenes. Converging evidence for this interpretation is that the
Not Told Group fixated the eyes more frequently in the test session than
in the study session.